Paper makers felt



June 18, 1963 I V. C. KElLY PAPER MAKERS FELT 5 Sheets-Sheet 1 FiledNov. 14, 1960 June 18, 1963' v. c. KElLY PAPER MAKERS FELT 5Sheets-Sheet 2 Filed NOV. 14. 1960 INVENTOR.

June 18, 1963 v. c. KEILY 3,094,149

PAPER MAKERS FELT Filed Nov. 14, 1960 5 Sheets-Sheet 3 INVENTOR.VINCE/V7 C. lfE/L) "TA/7M1 June 18, 1963 v. c. KEILY PAPER MAKERS FELT 5Sheets-Sheet 4 Filed Nov. 14, 1960 Afr/9 INVENTOR. w/vcnvr 6. XE/L) June18, 1963 v. c. KEILY PAPER MAKERS FELT 5 Sheets-Sheet 5 Filed Nov. 14,1960 INVENTOR.

M E H T N i a W United States Patent 3,094,149 PAPER MAKERS FELT VincentC. Kelly, Piqua, Ohio, assignor to The Orr Felt & Blanket Company,Piqua, Ohio, a corporation of Ohio Filed Nov. 14, 1960, Ser. No. 68,9972 Claims. (Cl. 139-383) This invention relates to felts for paper makingmachines, such as Fourdrinier or cylinder machines or the like, andparticularly to felts for the wet end of such a machine.

Paper makers felts of the nature referred to are extremely importantarticles of manufacture because they control the quality of paper beingmade and the speed at which it can be made. Such felts must exhibituniform drainage characteristics so that the liquor will drain properlyfrom the slurry or furnish that is flowed onto or picked up by the feltas the paper web is formed thereon.

The felts must also be quite strong and resistant to abrasion in orderto obtain a reasonable length of life thereof. Still further, such feltsmust exhibit uniform surface characteristics from end to end in order toassure the production of a uniform product.

Heretofore, paper makers felts have usual-1y been constructed of naturalfibers such as wool because these fibers have a natural felting tendencywhich provides for a product that is dimensionally stable and reasonablystrong.

Natural fibers, however, are lacking in being sufficiently resistant tochemical attack to provide for the best possible paper makers felt. Forexample, synthetic fibers are superior to natural fibers in resistingchemical and bacterial attack and are, furthermore, highly resistant toabrasion and exhibit great strength.

Accordingly, synthetic fibers have certain characteristics that :areideal for the manufacture of paper makers felts but the fibers areinferior with respect to producing a dimensionally stable fabric becausethe synthetic fibers are smooth and slippery and thus do not tend tofelt together as is the case with natural fibers, such as wool, whichhave serrated or irregular edge portions.

Synthetic fibers have been employed, however, successfully in themanufacture of paper makers felts by blending them with sufficient woolto obtain a felting action necessary for stabilizing the fabric. Inother cases, it has been found that felts can be made entirely ofsynthetic fibers by interlocking the fibers by a needling process bymeans of which the fibers become interlocked together and thus providefor a dimensionally stable felt.

Another method of producing a paper makers felt utilizing eithersynthetic or natural fibers involves the weaving of a backing and theapplication to at least one face thereof of a bat of fibers to form acomposite felt or fabric of the desired characteristics.

Such bats, when bats are applied to a base fabric, as referred to above,are laid across the woven base fabric in strips and the fabric isthereafter needled in a needle loom to bring about tight interlocking ofthe fibers of the bat to the base fabric. A process of this natureproduces a felt which has desirable characteristics but, it has beenfound that this manner of applying the bat to the base,

fabric does not produce an absolutely uniform distribution of the batmaterial so that the characteristics of the resulting end product arenot absolutely uniform as is most desirable with felts of this nature.

Furthermore, the fibers of a bat applied in this manner are not alltightly attached to the base fabric so that there is a tendency forthere to be a continuous loss of fibers from the felt which, of course,detracts from the quality of the product produced and from the usefullife of the felt.

Having the foregoing in mind, a primary object of the present inventionis the provision of a method of manu- "ice" 2, facturing a paper makersfelt' in which a bat is uniformlydistributed over the entire felt.

Another object of this invention is the provision of a method ofsupplying a bat to a base fabric to make a paper makers felt in whichsubstantially any desired surface characteristics on either side of thefelt can be obtained.

Still another object of this invention is the provision of an improvedpaper makers felt consisting of :a strong, dimensionally stable fabricand a bat uniformly distributed over the felt and needled thereto.

These and other objects and advantages of this invention will becomemore apparent upon reference to the following specification taken inconnection with the accompanying drawings in which:

FIGURE 1 is a diagrammatic representation of a loom producing a papermakers felt according to this invention;

FIGURE 2 is a diagrammatic representation of a needle loom in which thefelt is needled;

FIGURE 3 is an elevational view showing the appearance of a fabric wovenaccording to the present invention prior to needling thereof;

FIGURES 4, 5 and 6 are sectional views indicated by lines 4-4, 55, and66, respectively, on FIGURE 3;

FIGURE 6A is a sectional view indicated by line 6A--6A on FIGURE 3showing the manner in which the rovings or slivers rest on top of thefill threads of the base fabric after the fabric is beaten up in theloom;

FIGURE 7 is a perspective view showing another type of weave by which afelt can be made according to this invention;

FIGURE 8 is a plan view of the felt of FIGURE 7;

FIGURE 9 is a view of the felt of FIGURE 7 looking up from the bottom;

FIGURE 10 is a plan view of the felt of FIGURE 7 looking up from thebottom;

FIGURES 11 and 12 are sectional views indicated by lines 1111, 1212,respectively, on FIGURE 8;

FIGURE 12A is a sectional view indicated by line 12A-12A on FIGURE 8showing the rovings or slivers as they are actually disposed on top ofthe adjacent fill threads.

FIGURE 13 is a perspective view looking at the top of another type ofweave;

FIGURE 14 is a perspective view looking up from the bottom of the fabricof FIGURE 13;

FIGURES 15 and 16 are top and bottom plan views, respectively, of thefabric of FIGURE 13;

FIGURES 17 and 18 are sectional views indicated by lines 17-17 and18--18, respectively, on FIGURE 15;

FIGURE 18A is a sectional view indicated by line 18A--18A on FIGURE 15showing the rovings or slivers as they are actually disposed on top ofthe adjacent fill threads;

FIGURES 19 and 20 are perspective views looking at the top and bottom,respectively, of still another fabric woven according to the presentinvention;

FIGURES 21 and 22 are top plan and bottom plan views, respectively, ofthe fabric of FIGURE 19;

FIGURES 23 and 24 are sectional views indicated by lines 2323 and 24-24,respectively, on FIGURE 21;

FIGURE 24A is a sectional view indicated by line 24A-24A on FIGURE 21showing the rovings or slivers as they are actually disposed on top ofthe adjacent fill threads;

FIGURES 25 and 26 are top and bottom perspective views, respectively, ofstill another fabric woven according to this invention;

FIGURES 27 and 28 are top and bottom plan views, respectively, of thefabric of FIGURE 25;

FIGURES 29 and 30 are sectional views indicated by 3 lines 2929 and30-30, respectively, on FIGURE 27; and

FIGURE 30A is a view indicated by line 30A30A on FIGURE 27.

General Description The present invention accomplishes the severalobjectives referred to by providing for absolute uniform distribution ofbat material in a base fabric so that irregularities in the resultingfelt on account of joints of overlaps between adjacent strips of batmaterial are eliminated. According to the present invention, this isaccomplished by weaving the bat material into the base fabric in theform of a sliver of fibers which is put into the fabric in the same wayas the fill or weft threads.

In this manner, the distribution of the bat material is uniformthroughout the length of the felt, and from side to side thereof, andthe bat material can be inserted into the body of the felt in anydesired quantity and according to any desired distribution.

For example, there could be one pick of sliver for each pick of fillthread, or there could be more or fewer picks of sliver according to therequirements of the particular felt being woven.

Similarly, depending on the requirement of the felt being woven, theslivers being inserted with the fill threads could be placed therein soas to be uniformly disposed on opposite sides of the felt or so as tohave more exposure on one side than the other. Still further, differ entsets of slivers could be placed in the fabric with one being mostlydisposed in the upper surface and the other being mostly disposed in thelower surface where a two sided felt was the objective.

In any case, it will be apparent that the resulting product has a strongbody or base fabric formed by interwoven warp and fill threads anduniformly distributed in this base fabric are the fibers which impart tothe woven felt its surface characteristics and, in part, its drainagecharacteristics in the form of untwisted, or only slightly twisted,roving or slivers woven into the base fabric according to a uniformpreselected pattern. The weaving-in of the slivers of fibers completelyavoids the objections which usually characterize paper makers felt inwhich the fibers referred to are applied to the base fabric in the formof a bat.

Still further, a felt according to the present invention is found tohave the woven-in fibers more firmly anchored in the base fabric than isthe case with a felt in which the fibers are applied to the base fabricin the form of a bat. It is found that many of the fibers, when they areapplied to the base fabric in the form of a bat, are loosely joinedthereto and easily pull out, whereas with a felt according to thepresent invention, it is found that a much higher percentage, in fact,substantially all of the woven-in fibers are firmly anchored in the basefabric.

After the felt has been woven, it is treated according to knownpractices which include washing, processing the fabric through a needleloom, and shearing the nap, and other conventional steps, such asfulling.

In connection with the needling of the fabric, this can be done bypassing the fabric a plurality of times through a needle loom havingbarbed needles which penetrate the fabric a plurality of times for eachunit area, say, from 100 to 1000 or more per square inch. The fibers inthe base fabric and the woven-in fibers are thus forcibly entangled anddisplaced into interlocking relation With each other. Broadly, thiscorresponds to what occurs in the felting of natural fibers when thenatural fibers creep together as the fabric is worked, on account oftheir natural serrated edge portions.

Synthetic fibers, lacking such serrated edge portions, will onlyinterlock tightly when they are forcibly mechanically displaced intointerlocking relation. Still further, with synthetic fibers that areeither shrinkable or which can be heat set, this interlocking can bemade permanent so that high strength and high stability of 4 the feltresults when the felt is either shrunk or heat treated following theneedling operation.

When heat shrinking is to be accomplished, the synthetic fibers employedare shrinkable Dacron or any similar synthetic filament capable ofshrinking when subjected to heat.

By a heat settable fiber is meant one which can be softened by theapplication of heat so that after the fabric is needled and is then heattreated, the entangled interlocked filament will become permanently setwhether or not any actual shrinkage occurs. Ordinarily, even with fibersthat are referred to as heat settable" some shrinkage of say, aboutone-half percent to three percent will occur, whereas with theshrinkable fibers, shrinkages of from five to fifteen percent can occur.

Detailed Description FIGURES 3 through 6A show, somewhatdiagrammatically, one manner in which a paper makers felt can be wovenaccording to the present invention.

In FIGURES 3 through 6 the warp threads are indicated at 10 and theconventional fill threads are indicated at 12. Warp 10 and fill 12 makeup the base fabric and these threads can be of synthetic or all wool orany blend thereof.

The woven-in rovings or slivers are indicated at 14 and these arewoven-in according to a different pattern from the fill threads 12. Itwill be understood that the beating up of the felt as it is being wovenwill tend to crowd the fill threads and the slivers adjacent theretotogether so that the product as it comes from loom 16 will appearsomewhat differently than it does in the drawings. For the purpose ofclarification, however, the fill threads and the woven-in slivers areshown in FIGURES 3 through 6 in side by side relation.

The felt according to FIGURES 3 through 6 would be two sided because asmuch of the sliver material is exposed on the bottom of the fabric as isexposed on the top.

As mentioned before, in beating up the fabric in the loom, the rovingsor slivers are pushed over into position to cover the adjacent fillthreads and when the fabric is finished, the fill threads are normallyalways visible on the face of the fabric by pushing the rovings orslivers to one side. This comes about because the rovings or slivers arerelatively loose and fluffy and on the sides of the fabric where thereare Woven over three warp threads and then under one, they are pushedover the tops of the adjacent fill threads in the beating up of thefabric so as to conceal the fill threads and also so as to expose onthat side of the fabric a substantially continuous surface of the rovingor sliver material.

This is illustrated in FIGURE 6A which is a sectional view indicated onFIGURE 3 but which, it will be understood, is a view that isrepresentative of the fabric after 1t has been woven and as it comesdirectly from the loom.

In FIGURES 7 through 12 there is shown a somewhat different weave inwhich the warp threads are indicated at 18, the fill threads at 20 andthe woven-in sliver at 22. An inspection of these figures would showthat the sliver is exposed more on top of the felt than on the bottombecause it is woven over three warp threads then under one. The regularfill threads 20, on the other hand, are uniformly distributed in the topand bottom because they are woven over two warp threads and then undertwo.

With the felt of FIGURES 7 through 12, there would be strongly one sidedcharacteristics because most of the sliver material is on one side ofthe felt and the nap would upstand from the said one side.

The back of the felt would consist mostly of the exposed warp and fillthreads 18 and 20 and would sustain the abrasion to which the felt wouldbe subjected in use,

FIGURE 12A, which is similar to FIGURE 6A, shows the fabric of FIGURES 7through 12 more nearly as it appears when it emerges from the loom andillustrates the manner in which the roving or sliver material isdisposed on top of the adjacent fill threads.

FIGURES 13 through 18 show a felt substantially identical with the feltof FIGURES 7 through 12 except that the staggering of the points ofinterweaving of the sliver material with the warp threads is somewhatdifferently arranged. The reference numerals in FIGURES 13 through 18are the same as those employed in FIG- URES 7 through 12 with theaddition of a subscript a.

FIGURE 18A is a view similar to FIGURES 6A and 12A and also shows thefabric of FIGURES 7 through 12 more nearly as it appears when it emergesfrom the loom and illustrates the manner in which the roving or slivermaterial is disposed on top of the adjacent fill threads.

FIGURES 19 through 24 show still another felt woven according to thisinvention and in this case the amount of sliver material is increased byputting in two picks of sliver for each pick of fill thread. In theseviews, the warp threads are indiacted at 24, the fill threads at 26, andthe woven-in slivers at 28.

It will be noted that the felt of FIGURES 19 through 24 is also stronglyone sided because each sliver is exposed mostly to the top of the feltby being woven over three warp threads and under one. The points ofinterweave of the sliver material with the base fabric will, of course,stagger to provide for great strength and uniformity.

FIGURE 24A is a view similar to FIGURES 6A, 12A and 18A and pertains tothe fabric of FIGURES 19 through 24 and shows the fabric more nearly asit appears when it emerges from the loom and illustrates the manner inwhich the roving or sliver material is disposed on top of the adjacentfill threads.

In FIGURES 25 through 30 still another type of felt is illustrated whichis somewhat similar to the felt of FIG- URES 19 through 24 in that thereare two slivers for each fill thread but wherein the slivers are sowoven that the felt is two sided. In these figures, the warp threads areindicated at 30, the fill threads at 32 and the slivers at 34. It willbe noted that one group of slivers as at 34a, are interwoven with thewarp threads, three over and one under, so as to lie mostly in the topof the fabric whereas the other group of slivers at 34b are interwovenwith the warp threads, one over and three under, so as to lie mostly inthe back face of the felt. Felt of this nature can be made completelytwo sided so that it can be run with either face out, and so that it canbe turned out, if

necessary.

FIGURE 30A is a view similar to 6A, 12A, 18A and 24A and pertains to thefabric of FIGURES 25 through 30 and shows the fabric more nearly as itappears when it emerges from the loom and illustrates the manner inwhich the roving or sliver material is disposed on top of the adjacentfill threads.

The warp and fill threads making up the body of the fabric areinterwoven the same as in connection with the two previously describedmodifications.

From the foregoing, it will be appreciated that many other weavepatterns could be employed while practicing the present invention. Theimportant characteristic in any case is the weaving into the base fabricof the fibers that are to determine the surface characteristics of thecompleted product in the form of untwisted or slightly twisted rovingsor slivers according to a predetermined fixed weaving pattern.

As mentioned before, it has been found that the resulting felt is farsuperior with respect to uniformity of surface and drainagecharacteristics than felts with a needledin bat and that the feltaccording to this invention has great strength and dimensionalstability.

In the foregoing specification and in the appended claims, rovings andslivers is intended to mean substantially untwisted or slightly twistedbundles of fibers somewhat like a yarn having only sufiicient twistthereto to retain the fibers in the form of a bundle that can be handledby the loom equipment. This would mean that sometimes the roving orsliver would be completely untwisted and in some cases there would be aslight twist in the roving or sliver.

The weaving-in of the slivers is accomplished by using a shuttle in thesame manner as the regular fill threads are woven into the fabric. Itwill be understood that the slivers, where necessary, will havesufficient twist to retain them in the form of a bundle and to bind themtogether so that they would not be pulled apart when the shuttle passesfrom one side of the loom to the other.

It will also be understood that the conventional tensioning devices thatare placed in the shuttle in order to maintain a predetermined tensionon the fill threads would be adjusted to a minimum tension position, orpreferably removed entirely, so that the minimum amount of the loadwould be placed on the slivers during the weaving process. In thismanner, it is possible to weavein the slivers without breakage, eventhough the slivers are completely untwisted or only slightly twisted.

It is understood that the appended claims are intended to cover bothtwisted and slightly twisted fiber bundles.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions; and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

I claim:

1. A paper makers felt comprising a base fabric comsisting of interwovenwarp and fill threads, said base fabric comprising slivers of fibrousmaterial interwoven with the fabric parallel with the fill threads anduniformly distributed in the fabric, said warp and fill threads andslivers of fibrous material being tightly interlocked, said fill threadsbeing woven over two warp threads and then under two warp threads, andsaid slivers consisting of two groups, the members of which alternatewith each other, the members of one group being disposed mostly in oneface of the fabric and the members of the other group being disposedmostly in the other face of the fabric, said slivers being woven intothe base fabric in pairs with a fill thread being disposed on theopposite sides of each pair of slivers.

2. A paper makers felt comprising a base fabric consisting of interwovenwarp and fill threads, said base fabric comprising slivers of fibrousmaterial interwoven with the fabric parallel with the fill threads anduniformly distributed in the fabric, said warp and fill threads andslivers of fibrous material being tightly interlocked, said fill threadsbeing woven over two warp threads and then under two warp threads, andsaid slivers consisting of two groups, the members of which alternatewith each other, the members of one group being disposed mostly in oneface of the fabric and the members of the other group being disposedmostly in the other face of the fabric, said slivers being woven intothe base fabric in pairs with a fill thread being disposed on theopposite sides of each pair of slivers, and said felt having a raisednap on one side thereof.

References Cited in the file of this patent UNITED STATES PATENTS Re.21,890 Walsh et al. Aug. 26, 1941 630,573 Smith Aug. 8, 1899 1,807,785Gillies June 2, 1931 2,303,534 Foster Dec. 1, 1942 2,390,386 RadfordDec. 4, 1945 2,792,851 Moeckel May 21, 1957 FOREIGN PATENTS 908,657France Oct. 11, 1945 641,671 Germany Feb. 10, 1937 801,439 Great BritainSept. 17, 1958

1. A PAPER MARKERS FELT COMPRISING A BASE FABRIC CONSISTING OFINTERWOVEN WARP AND FILL THREADS, SAID BASE FABRIC COMPRISING SLIVERS OFFIBROUS MATERIAL INTERWOVEN WITH THE FABRIC PARALLEL WITH THE FILLTHREADS AND UNIFORMLY DISTRIBUTED IN THE FABRIC, SAID WARP AND FILLTHREADS AND SILVERS OF FIBROUS MATERIAL BEING TIGHTLY INTERLOCKED, SAIDFILL THREADS BEING WOVEN OVER TWO WARP THREADS AND THEN UNDER TWO WARPTHREADS, AND SAID SLIVERS CONSISTING OF TWO GROUPS, THE MEMBERS OF WHICHALTERNATE WITH EACH OTHER, THE MEMBERS OF ONE GROUP BEING DISPOSEDMOSTLY IN ONE FACE OF THE FABRIC AND THE MEMBERS OF THE OTHER GROUPBEING DISPOSED MOSTLY IN THE OTHER FACE OF THE FABRIC, SAID SLIVERSBEING WOVEN INTO THE BASE FABRIC IN PAIRS WITH A FILL THREAD BEINGDISPOSED ON THE OPPOSITE SIDES OF EACH PAIR OF SLIVERS.